Potential of sewage sludge as soil amendment

Nowadays, the volume of sewage sludge is increasing parallel with the increases in population of Malaysia. The cost to treat the sludge is very high and longer time is needed for the treatment. One of the methods that is generally use in Malaysia to treat the sludge is composting but unfortunately this method takes longer duration for the sludge to be treated for used as soil conditioner. Thus, soil amendment is introduced to improve the existing method. Sludge as soil amendment seems to become the ultimate solution for sludge management. This study was conducted to assess the suitability of sewage sludge as soil amendment for plant. Three samples have been prepared for each ratio of dried leaves and lime powder: dried sludge. Proportions of sewage sludge to the dried leaves as used in study are 1:2, 1:3 and 1:4. The results indicated the decreased in heavy metals in the sludge. The additional material for soil amendment is dried leaves and the best mixing proportion is 1:4.